EN
During a post-mortem examination of 53 birds from 25 species in 11 birds abormalities in anatomical structure or position of coeca were found. These abnormalities included a shortened one coecum comparing to other one, a firm connection of coecum with ileum, asymetrial position of both coeca. These changes point to changeability of coeca in some species of birds. The changes were noted in 3 waswings, 2 yellowhammers, 1 maffinch, songtrush, blackbird and swallow. In two robins the third coecum as a developmental disturbance was found.